Have you ever watched how Bill Clinton shakes hands. He doesn’t just clasp your right hand in his, he also touches your arm with his left hand. During the conversation, as he makes a point, he might reach out again to touch your arm or put his hand on your shoulder.

Clinton’s use of nonsexual touching is, arguably, one of the reasons people seem to like him so much. (No comments about his alleged use of other kinds of touching, however.)

According to psychologists, touch “can influence behavior, increase the chances of compliance, make the person doing the touching seem more attractive and friendly, and can even you help make a sale.”

Tests have shown that when touched, people are more likely to comply with requests, more likely to provide help, and more likely to buy. And touching more than once seems to increase these results.

Indiscriminate touching, however, could backfire. In a school or work place setting, any kind of touching could be misinterpreted. In some cultures, touching is generally less welcome than in others. And some individuals don’t like to be touched under any circumstances.

By and large, the rewards are probably worth the risks. Just use common sense when meeting someone new. A pat on the arm or the shoulder is probably safe. A lingering full body hug, probably not a good idea, even for Bill Clinton. Especially for Bill Clinton.